The present invention relates generally to air diffuser outlets compatible with suspended ceiling air conditioning systems, and, more particularly, to the provision of a dual flow nested plenum chamber construction and improved weir control surfaces using jet pair weir gates to improve the effectiveness and controllability of air diffusion outlets installed in suspended ceilings.
The improved diffuser outlet disclosed herein incorporates the same construction and operating advantages as conventional diffuser outlets such as those disclosed in U.S. Pat. No. 3,411,425 entitled "AIR DIFFUSION OUTLET WITH LATERALLY ADJUSTABLE WEIR CONTROL" issued Nov. 19, 1968 to the common inventor of this application, namely, construction that permits mounting of the outlet flush with the surface of a suspended ceiling (suspended from the undersurface of the permanent floor or roof of a building, herein referred to as the soffit), placement adjacent to light panels or fixtures as well as points distant therefrom, and of various sizes that are readily adjusted for cooperation with air supply ducts of different sizes and necks, and providing means for controlling the direction of airflow therefrom. U.S. Pat. No. 3,411,425 particularly provides for the use of an adjustable weir that is comprised of a pair of U-shaped channel members that are in an opposed, nested relationship such that they can laterally expand and contact to selectively and variably obstruct the opening of a diffuser outlet to control the volume and direction of a diffused airflow. This construction is compatible with a single plenum chamber and can utilize the horizontal flange of a suspended ceiling T-bar to direct and diffuse the airflow.
While the various diffusers disclosed in said patent provide a type of diffused airflow that works well for many applications, there are some instances where a more focused airflow, as well as two types of airflow from a single diffuser, are highly desirable. This is particularly true for air conditioning systems that must operate in a non-homogeneous, more hostile environment. One such environment is the room that contains large glass windows exposed to either a significantly hotter or significantly colder external environment. These windows tend to be highly conductive and, by convection due to the resulting temperature gradient, can rapidly alter the temperature and character of a diffusive airflow in their vicinity, thus preventing said room from attaining a uniform, comfortable temperature and airflow without the use of an excessive number of diffuser outlets or the utilization of a large and costly volume of conditioned air.